Fix issue with wrong report name

When splitting a report path provided on JCommander, given a Windows path
would cause a false split, that would continue the execution despite the assert check.

This commit fixes this issue by the assumption that an absolute path on Windows
systems, will contain the current disk drive's letter.

Resolves: detekt#1123 - detekt#1141

detekt-cli/src/main/kotlin/io/gitlab/arturbosch/detekt/cli/ReportPath.kt

@@ -11,10 +11,24 @@ import java.nio.file.Paths
  */
 data class ReportPath(val kind: String, val path: Path) {
 	companion object {
+		private const val NUM_OF_PARTS_UNIX = 2
+		private const val NUM_OF_PARTS_WINDOWS = 3
+		private const val REPORT_PATH_SEPARATOR = ":"
+		private const val ILLEGAL_PARTS_SIZE_ERROR = "Must consist of two parts for Unix OSs or three for Windows (report-id:path)."
+
 		fun from(input: String): ReportPath {
-			val parts = input.split(":")
-			assert(parts.size == 2) { "Must consist of exactly two parts (report-id:path)." }
-			val (kind, path) = parts
+			val parts = input.split(REPORT_PATH_SEPARATOR)
+			val partsSize = parts.size
+
+			require(partsSize == NUM_OF_PARTS_UNIX || partsSize == NUM_OF_PARTS_WINDOWS) { ILLEGAL_PARTS_SIZE_ERROR }
+
+			val kind = parts[0]
+			val path = when (partsSize) {
+				NUM_OF_PARTS_UNIX -> parts[1]
+				NUM_OF_PARTS_WINDOWS -> parts.slice(1 until partsSize).joinToString(REPORT_PATH_SEPARATOR)
+				else -> throw IllegalStateException(ILLEGAL_PARTS_SIZE_ERROR)
+			}
+
 			return ReportPath(defaultMapping(kind), Paths.get(path))
 		}
 

detekt-cli/src/test/kotlin/io/gitlab/arturbosch/detekt/cli/out/ReportsSpec.kt

@@ -25,14 +25,15 @@ internal class ReportsSpec : Spek({
 				"--input", "/tmp/must/be/given",
 				"--report", "xml:/tmp/path1",
 				"--report", "plain:/tmp/path2",
-				"--report", "$reportUnderTest:/tmp/path3"
+				"--report", "$reportUnderTest:/tmp/path3",
+				"--report", "html:D:_Gradle\\xxx\\xxx\\build\\reports\\detekt\\detekt.html"
 		)
 		val (cli, _) = parseArguments<CliArgs>(args)
 
 		val reports = cli.reportPaths
 
 		it("should parse multiple report entries") {
-			assertThat(reports).hasSize(3)
+			assertThat(reports).hasSize(4)
 		}
 
 		val extensions = ReportLocator(ProcessingSettings(listOf())).load()